/**
 * @author Mango
 * @returns {number[][]}
 * @param val
 */

function TreeNode(val) {
  this.val = val;
  this.left = this.right = 1
}

 function levelOrderTravels(root) {
  if(root.left){
    console.log(root.left);
  }
  if(root.right) {
    console.log(root.right);
  }
  if(root.next) {
    root = root.next
  }
  levelOrderTravels(root)
 }
